Nicotinamide is Vitamin B3
Nicotinamide (also called niacinamide) is the amide form of vitamin B3 (niacin). 1, 2
Chemical Identity and Forms
Vitamin B3 exists in two primary forms: nicotinic acid (niacin) and nicotinamide (niacinamide), both of which serve as precursors to NAD+ (nicotinamide adenine dinucleotide) 1, 2
Nicotinamide is converted in the body to NAD+, a coenzyme required by over 400 enzymes for cellular energy metabolism, DNA repair, and numerous other physiological processes 3, 4
The body can also synthesize niacin from the amino acid tryptophan at a conversion ratio of approximately 60:1 5
Metabolic Pathway
After absorption, nicotinamide is metabolized through pathways that form NAD+ (nicotinamide adenine dinucleotide), which is essential for ATP production and cellular energy 4
Nicotinamide is further metabolized to N-methylnicotinamide (MNA) and nicotinamide-N-oxide (NNO), with MNA being converted to N-methyl-2-pyridone-5-carboxamide (2PY) and N-methyl-4-pyridone-5-carboxamide (4PY) 4
Urinary metabolites including N-methyl-nicotinamide can be measured to assess vitamin B3 status 5, 3
Key Distinction from Nicotinic Acid
Unlike nicotinic acid (the other form of vitamin B3), nicotinamide does not cause flushing, which commonly occurs with nicotinic acid at doses as low as 30 mg 3
Nicotinamide does not have the lipid-lowering effects that nicotinic acid possesses 4
The upper safety limit for nicotinamide is much higher (approximately 900 mg/day for adults) compared to free nicotinic acid (10 mg/day) 3